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#3351 Re: Guestbook » Basic PHP Math Question » 2011-01-17 18:51:34

gAr

Hi simy202,

I guess you haven't read about operator precedence.
Please refer this: http://www.php.net/manual/en/language.operators.precedence.php

echo((1  + 2 + $var1) * $var2) / 2 - 5;

This evaluates to : (((1 + 2 + 3)*4)/2) - 5 = ((6*4)/2) - 5 = 12 - 5 = 7.
If you want it to be -8, rewrite it as:

echo((1  + 2 + $var1) * $var2) / (2 - 5);

The left of '=' sign is called Left hand side, not the left of '/' sign...

#3352 Re: Exercises » What do you think? » 2011-01-17 17:44:30

gAr

Hi bobbym,

I was simply trying to verify for different n values.
Here is the answer I believe to be true.

#3353 Re: Exercises » What do you think? » 2011-01-17 16:04:00

gAr

Hi Howardroark,

Yes, minimum is 336. I was wondering whether the answer will be the same for any n ≥ 336, and I'm sure bobbym checks it before posting the questions. It is relatively easy for n = 336.

#3354 Re: Exercises » What do you think? » 2011-01-17 14:39:16

gAr

Hi bobbym,

Here is the newest killer:

When n dice are rolled, the probability of obtaining a sum of 2011 is the same as the probability of obtaining a sum of s. What is the smallest value of s?

I was asking about this, you posted 10 days ago...

#3355 Re: Exercises » What do you think? » 2011-01-17 05:42:08

gAr

For the n dice problem, is it possible to do without knowing the value of n? Will it hold true for every n?

#3356 Re: Maths Teaching Resources » some amazing apps » 2011-01-17 02:09:52

gAr

Hi,
I observe that carmetal is better at plotting implicit equations...
But figure does not scale well, the sine curve looks like a line, unless I multiply it by a constant and zoom out.
Anyway, I really appreciate both geogebra and CaR. I find Geogebra easier to use.

#3357 Re: Maths Teaching Resources » some amazing apps » 2011-01-17 00:26:47

gAr

Hi bobbym,

I haven't used the softwares in depth. Hence I can't tell which has better features!
Can I plot trigonometric functions in any of them?

#3358 Re: Exercises » What do you think? » 2011-01-17 00:20:02

gAr

Oh good!
I see, you have customized it. I have it installed as well.

#3359 Re: Maths Teaching Resources » some amazing apps » 2011-01-17 00:00:23

gAr

Check this out as well: http://processing.org/

#3360 Re: Exercises » What do you think? » 2011-01-16 23:56:03

gAr

Ah, nice! One more lesson for me not to go with intuition! My thought gave me about .05 extra.
Which software did you use for the diagram?

#3361 Re: Maths Teaching Resources » some amazing apps » 2011-01-16 23:10:46

gAr

CaRmetal is another interactive geometry software. It looks neat. It can even plot implicit fuctions.
Check it out: http://db-maths.nuxit.net/CaRMetal/index_en.html

#3365 Re: Help Me ! » Distance problems » 2011-01-16 15:03:40

gAr

Hi Mariner,
If you are comfortable with usual multiplication, go ahead by converting mins to hrs, and multiply.
E.g. D = 72km/h * (5 + 24/60)h = 360 + 144/5 = 388.8km
Make sure about the units.
If you want a fast way, learn "Vedic mathematics".

#3366 Re: Exercises » What do you think? » 2011-01-16 01:58:41

gAr

Hi bobbym,

Ok, I'll try

#3368 Re: Exercises » Is this cool with you? » 2011-01-15 15:14:27

gAr

Hi bobbym,

There may be people who know and choose not to post the same solution again. They may post a solution if they find another way of solving it...

#3369 Re: Exercises » Is this cool with you? » 2011-01-15 02:45:47

gAr

Thanks bobbym,
Nice problem on tetrahedral numbers...

#3371 Re: Exercises » Race with possibility of ties (permutations!) » 2011-01-15 01:01:07

gAr

Yes bobbym, really so many of them.
It must be the first place to go to know a function!

#3373 Re: Exercises » Race with possibility of ties (permutations!) » 2011-01-14 21:19:29

gAr

I came across a list of formulas summarised in wolfram's site: http://functions.wolfram.com/IntegerFunctions/StirlingS2/

#3375 Re: Exercises » Race with possibility of ties (permutations!) » 2011-01-13 23:30:54

gAr

hmmm, I'll follow the advice this time.

Me modest, humbug! Nah, no one has read any of it.

This may be false!!

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